A lot depends on the cycle. The body will seek to normalize after the cycle, and again after PCT stops. This is why bloodwork is VERY important. You can choose to have a pharma AI or OTC AI on hand, in fact you should always have both ready just in case. If you stop PCT and you develop nipple sensitivity, puffyness, or gland enlargement, use an AI. If PCT ends and you develop no sides of increased estrogen (to an unsafe level), you're good to go.